It is known in the art to provide a slide fastener in which the two slide-fastener halves for the coupling heads of the coupling elements formed by continuous monofilament coupling coils, are woven into the support tapes which themselves are woven. There are certain structures which characterize this class of slide fasteners. For example, the coupling heads may be formed by bends of the coupling coils, the shanks extending rearwardly from the heads may be superimposed in projection on the slide-fastener plane, the shanks can be formed as double wefts and the tape can be formed from double wefts formed by a continuous weft filament or yarn providing the ground weft, and warp yarns can be interwoven with the double wefts and can form binding warp yarns retaining the coupling weft or coil on the tape.
The German Patents 30 09 276 and 30 22 032 describe such systems; various configurations of the binding warp yarns and different ratios of the warp insertion to the length of the slide fastener are used, but the arrangement is always such that two coupling elements are contained in a warp yarn pocket.
In DE 28 55 370, a different type of slide-fastener stringer is described, in which the binding warp yarns may have a similar pattern to those of the instant invention but it will be recognized that the binding warp yarns of the first group here do not, following the overshoot of the coupling elements, engage below the next double weft of the ground weft yarn. In addition, the coupling elements are not formed as synthetic resin monofilament double-weft insertions and thus cannot be fabricated by a weaving process involving one or two weft insertion needles as can be the stringer of the invention. The coupling element must be formed in this earlier system by a machine which is alien to the tape fabrication machines utilizing such insertion needles, namely, with the aid of a coiling machine having a coiling mandrel so that the coils can be woven into the tape only within the weaving shed.
These systems are expensive and have low productivity and the nature of the binding of the coupling coil in place does not enhance bendability. Indeed, the bending characteristics are determined by the presence of a filler yarn. The resistance to raveling and change of shape at the junction between the coil and the tape is not equivalent to that which can be obtained with the present invention however. The double wefts of the ground weft yarns pass over the connecting bights of the coupling elements, come into contact with the flanks of the slider and are relatively rapidly deteriorated.
This system has been found to be effective, but the stiffness with respect to bending in the slide-fastener plane and out of the slide-fastener plane can be improved upon. Also the connection between the coupling coil and the web, its resistance to deterioration in use and the like can be improved upon.